Field of the Invention
The present disclosure relates to a flexible organic light emitting display apparatus that can be used as a flexible display apparatus and a method of manufacturing the same.
Discussion of the Related Art
Recently, the field of display apparatuses, which visually express an electrical information signal, is rapidly advancing. Therefore, research is being continuously conducted for developing flat panel display (FPD) and other types of display apparatuses having excellent performance such as thinness, lightness, low power consumption, etc. Representative examples of such FPD apparatuses include liquid crystal display (LCD) apparatuses, plasma display panel (PDP) apparatuses, field emission display (FED) apparatuses, electro-wetting display (EWD) apparatuses, etc. The FPD apparatuses each include a flat display panel for realizing an image. The FPD apparatuses each have a structure where a pair of substrates are bonded facing each other with a unique emitting material or polarizing material therebetween, and includes a display which has a display area and a non-display area at a periphery of the display area. The display area is defined as an area having a plurality of pixels.
Recently, flexible display apparatuses which use a flexible substrate formed of a flexible material such as plastic, and can maintain a display performance despite being bent like paper, are being developed for replacing the FPD apparatuses. Such flexible display apparatuses may be widely applied to various fields compared to existing display apparatuses with no flexibility, and thus, research and development for commercializing the flexible display apparatuses are being done continuously. Also, OLED apparatuses display an image by using an organic light emitting device which is a self-emitting device. That is, the OLED apparatuses each include a plurality of pixels which each include an organic light emitting device.
The organic light emitting device includes first and second electrodes, which face each other, and an emission layer which is formed of an organic material between the first and second electrodes and emits electroluminescent light, based on a driving current between the first and second electrodes. However, the emission layer formed of an organic material is easily and quickly deteriorated due to water and oxygen. Water may be referred as moisture, water or vapor. Therefore, general organic light emitting display apparatuses include an encapsulation part that protects water and oxygen from permeating into an organic layer. Generally, the encapsulation part uses an inorganic substrate which has an excellent characteristic of delaying the permeation of water.
General organic light emitting display apparatuses each include an array substrate where a plurality of thin film transistors (TFTs) are formed, a pixel part which is provided on the array substrate and includes an organic light emitting device driven by a plurality of TFTs, and an encapsulation part that seals the array substrate with the pixel part therebetween.
When a water/oxygen permeation path occurs in the encapsulation part, lifetime and reliability of an organic light emitting display apparatus are reduced.
The encapsulation part of the related art has a multi-layer structure where a silicon-based organic insulation layer, a silicon-based inorganic insulation layer, a silicon-based organic insulation layer, and a silicon-based inorganic insulation layer are repeated in order multiple times. However, the encapsulation part is thick, and thus, when the encapsulation part is bent, a crack easily occurs. For this reason, it is difficult to apply the encapsulation part of the related art to a flexible display apparatus.